<p>Because it retrieves all instructions and data from a single memory, the von Neumann computer architecture has a fundamental speed limit. The scalable multicomputer architecture, which uses many microprocessors together to solve a single problem and can run at teraflop speeds, may be a solution. While teraflop processor technology is known, the scalable operating and I/O system technology necessary for those speeds are not known. The authors describe how Unix can be extended to scalable computing, permitting teraflop speeds and offering parallel computing to users unfamiliar with parallel programming. They designed this technology into the system software of the Ncube-2, the predecessor to Ncube's announced teraflop parallel computer. The authors describe the system in detail and provide some performance results.</p>